Data Flow Diagram

BNO085 Sensor (I2C/SHTP) → Arduino ESP32 → [SPI] → FPGA → [SPI] → STM32 MCU → DAC → Speaker

Communication Protocols: - I2C/SHTP: BNO085 sensor to Arduino ESP32 - SPI: Arduino ESP32 to FPGA (ESP32 = master, FPGA = slave) - SPI: FPGA to STM32 MCU (MCU = master, FPGA = slave) - DAC: STM32 MCU to Speaker (12-bit DAC on PA4)

BNO085 IMU Sensor

The BNO085 is a 9-axis intelligent IMU that integrates an accelerometer, gyroscope, and magnetometer with an onboard sensor-fusion processor. Instead of exposing raw sensor registers directly, the BNO085 communicates through the Sensor Hub Transport Protocol (SHTP) — a structured, packet-based protocol that runs over standard physical interfaces including I²C, SPI, or UART.

Key Features: - Onboard ARM Cortex-M0+ microcontroller running Bosch’s BSX Lite fusion firmware - Performs sensor fusion (combining accel + gyro + mag) internally - Provides high-level motion data like quaternions and rotation vectors - Offloads computational cost of sensor fusion from host processor - Well-suited for high-performance embedded applications

SHTP Protocol: - Organizes communication into channels (configuration, sensor data, control/status) - Each channel maintains sequence numbers for reliable packet delivery - Packet structure: 4-byte header (length, channel, sequence) + payload (Report ID + sensor data) - Continually sends report packets at configured update rate

Arduino Nano ESP32

The Arduino Nano ESP32 combines the ESP32-S3’s processing power with the Arduino ecosystem, providing: - Integrated Wi-Fi and Bluetooth connectivity - Larger memory capacity for advanced sensor-fusion libraries - Easy integration with Adafruit_BNO08x library

Library Integration: - Uses Adafruit_BNO08x library for high-level BNO085 interface - Abstracts low-level SHTP packet parsing - Simple API calls for initialization, report enabling, and data retrieval - I2C communication with default address (0x4A)

Library: Adafruit_BNO08x

FPGA (UPduino)

The FPGA serves as a data bridge between the Arduino ESP32 and STM32 MCU: - Receives sensor data from ESP32 via SPI (slave mode) - Processes and packages data into custom transmission format - Sends packaged data to STM32 MCU via SPI (slave mode) - Implements dual SPI slave interfaces

FPGA Design Details: - Top-level module: drum_trigger_top.sv - Arduino SPI slave: arduino_spi_slave.sv - MCU SPI slave: spi_slave_mcu.sv - System clock: 3MHz (48MHz HSOSC divided by 16)

STM32 MCU

The STM32L432KC microcontroller: - Receives gesture data from FPGA via SPI (master mode) - Unpacks WAV files from flash memory (parsing RIFF headers and extracting audio samples) - Identifies which drum corresponds to detected motion input - Plays audio samples through 12-bit DAC on PA4 at correct sample rate - Drives speaker to play the correct drum sound

MCU Design Details: - SPI1 master configuration (PB3=SCK, PB5=MOSI, PB4=MISO, PA11=NSS) - DAC output on PA4 - Flash memory for WAV file storage

SPI Communication: ESP32 → FPGA

Configuration: - Clock Speed: 100kHz - Mode: SPI Mode 0 (CPOL=0, CPHA=0) - Bit Order: MSB first - CS Pin: D10 (FPGA_SPI_CS)

Packet Format (16 bytes): - Byte 0: Header (0xAA) - Bytes 1-2: Roll (int16_t, MSB first, scaled by 100) - Bytes 3-4: Pitch (int16_t, MSB first, scaled by 100) - Bytes 5-6: Yaw (int16_t, MSB first, scaled by 100) - Bytes 7-8: Gyro X (int16_t, MSB first, scaled by 2000) - Bytes 9-10: Gyro Y (int16_t, MSB first, scaled by 2000) - Bytes 11-12: Gyro Z (int16_t, MSB first, scaled by 2000) - Byte 13: Flags (bit 0 = Euler valid, bit 1 = Gyro valid) - Bytes 14-15: Reserved (0x00)

SPI Communication: FPGA → MCU

Configuration: - Mode: SPI Mode 0 (CPOL=0, CPHA=0) - Bit Order: MSB first - FPGA passes raw 16-byte packet buffer directly to MCU - MCU reads data via SPI master transactions

SPI Data Transmission: ESP32 → FPGA

Validation Using Logic Analyzer

The SPI bus was monitored using a logic analyzer to verify correct data transfer between the Arduino ESP32 and the FPGA. The captured waveform confirms that the expected byte sequence is transmitted from the Arduino to the FPGA when new motion data is available.

Validated Packet Example:

Results: - Decoded values match Arduino serial monitor output - SPI protocol functioning correctly - Data formatting matches intended system design - Arduino-to-FPGA communication pipeline is reliable

SPI Data Transmission: FPGA → MCU

Validation Using Logic Analyzer

The SPI communication between FPGA and MCU was validated using a logic analyzer, confirming correct data transfer and protocol compliance.

DAC Output

The 12-bit DAC on PA4 successfully outputs audio samples at the correct sample rate, enabling real-time drum sound playback through the speaker.

System Block Diagram

TODO: Add complete system block diagram

Please add a high-level system block diagram showing: - BNO085 sensor with I2C connection to Arduino ESP32 - Arduino ESP32 with SPI connection to FPGA - FPGA with SPI connection to STM32 MCU - STM32 MCU with DAC connection to speaker - Data flow arrows indicating direction - All communication protocols labeled (I2C/SHTP, SPI) - Bus widths indicated

Recommended Image Specifications: - Format: PNG or SVG - Size: 1200px width minimum - Location: Save to Images/system-block-diagram.png

Example:

![System Block Diagram](Images/system-block-diagram.png){width="100%" alt="Complete system block diagram"}

Pin Connection Diagram

TODO: Add pin connection diagram

Please add a comprehensive pin connection diagram showing: - All interconnections between components - Signal names and pin numbers - Power and ground distribution

Key Source Files

FPGA: - drum_trigger_top.sv - Top-level module - arduino_spi_slave.sv - Arduino SPI slave interface - spi_slave_mcu.sv - MCU SPI slave interface

MCU: - main.c - Main application code - STM32L432KC_SPI.c - SPI driver - WAV file parsing and DAC output code

Arduino: - ARDUINO_SENSOR_BRIDGE.ino - Sensor bridge code using Adafruit_BNO08x library

Finished Design Photos

TODO: Add photos of the complete system

Please add photos showing: - Complete assembled system - BNO085 sensor connection - FPGA board close-up - MCU board close-up - Arduino/ESP32 setup - Wiring and connections - Speaker and audio output

Recommended Specifications: - Format: JPG or PNG - Size: 1500-2000px width minimum - Location: Save to Images/ directory

Example:

![Complete System](Images/system-assembly.jpg){width="100%" alt="Complete assembled system"}

Video Demonstration

TODO: Add video link or embed

Please add your demonstration video showing: - System overview and setup - Air gesture detection - Real-time drum sound playback - Multiple drum sounds being triggered - Low latency demonstration

Video Requirements: - Hosted in the provided Google Drive folder - Named: <LastName1><LastName2><VideoName> (e.g., BellidoStralkaInvisibleDrumSet) - Shows the complete system in operation

Embedding Options: - Google Drive embed (iframe) - Direct link to Google Drive - YouTube/Vimeo embed